Yes, scientific articles are expensive. I know that, that sucks. That's why most of this stuff is on arxiv.
I linked to evidence that mathematicians are using LLMs to find proofs and publish those proofs. Which is what I said is happening.
I am not a mathematician, thus I don't really know where to find indipendent confirmation or even how that is generally handled by mathematicians. However: there are plenty proofs on arxiv that disclose have been found with LLMs. Some of these proofs relate to famous problems and have been in the news. Fields medal winners discuss the importance of LLMs and how it may produce too many proofs for humans to handle.
I trust that those proofs published on arxiv have been reviewed by many mathematicians, if they were incorrect that would have rapidly become known.
Scientists don't often publish when they confirm an article is correct. Knowing a few mathematicians, probably they see no need to do that. They checked the proof, it was ok and that's it.
Either way, many of those proofs come with a computer program which checks and confirms the proof is correct.
I trust that an expert mathematician talking about such things has reviewed a few of those articles and has checked the proof.
You may not do that; check the proof yourself or pay a mathematician to do it for you.